Engine governor with excess fuel device



Mmh 31, 1970 K. w. UPDYKIE 3,503,305

ENGINE GOVERNOR WITH EXCESS FUEL DEVICE Fi ril 24, 1968 INVENTOR KENNETH. W. UPDYKE ATTORNEYS United States Patent 3,503,305 ENGINE GOVERNOR WITH EXCESS EUEL DEvrcE Kenneth W. Updyke, Peoria, 111., assignor to Caterpillar Tractor Co., Peoria, 11]., a corporation of California Filed Apr. 24, 1968, Ser. No. 723,694 Int. Cl. F15b 9/02, 15/17; F02c 9/04 US. Cl. 91366 2 Claims ABSTRACT OF THE DISCLOSURE A spring in series with the servo valve of a known hydro-mechanical governor, which spring causes the fuel pump rack to move past its full load setting and permit excess fuel to be injected into the engine during starting.

This invention relates to an improvement in a double acting hydraulic servo governor such as that shown in US. Patent No. 3,145,624 to Parks et al. and assigned to the assignee hereof. More specifically, the invention relates to the use of a spring in series with the servo valve of such a hydro-mechanical governor which causes the fuel pump rack to move past its full load setting and permit excess fuel to be directed into the engine for starting purposes.

The maximum fuel delivery of a fuel injection system is generally limited by a full load stop that permits the required amount of fuel to be delivered to an engine when the engine is operating under its designed full load. To facilitate starting of the engine, it is often necessary to provide an amount of fuel which is greater than that allowed by the full load stop. The extra fuel for starting is gained by utilizing an excess fuel device which may be manually or automatically controlled. Manual controls are often not desirable, since they must be reset each time the engine is started. Automatic excess fuel devices using hydraulic means have a disadvantage in that they are inoperable for a time after engine oil pressure rises during engine cranking. Therefore, if a false start occurs, the excess fuel device is inoperable until the oil bleeds from the device.

It is therefore an object of the present invention to provide apparatus for allowing the engine fuel pump to deliver the required amount of fuel for starting without the need of being manually set, or interfering with normal governor operations when the engine is running.

It is also an object of this invention to provide a dual acting hydraulic servo governor with an inexpensive means for providing sufficient fuel to the engine during starting, while not interfering with normal operation.

Further and more specific objects and advantages of the invention will become apparent upon reading the following specification wherein a preferred embodiment of the invention is described by reference to the accompanying drawing.

The drawing is a side elevation sectional view of the governor of the present invention with parts broken away.

Referring to the drawing, a governor 11 has a bifurcated control lever 13 which engages a spring seat 15 that is slidable on a support member 17. When lever 13 is rotated counter-clockwise, the spring seat 15 is urged to the right, as shown in the drawing, compressing a governor spring 19 against an adapter 21. The adapter is restricted in its movement to the right by a rod 23 having a shoulder 25 engaging a complementary shoulder 27 on the adapter. Rod 23 is limited in its rightward movement by retainer 29 which abuts a stop 31.

A spring 33 extends between a face 35 on the adapter and a face 37 on a sleeve 39. This causes the sleeve to be biased toward the right against thrust member 41. The movement of sleeve 39 is limited with respect to the adapter by a clip 43 extending about the periphery of the Patented Mar. 31, 1970 sleeve in a groove 45. A pin 47 fixes a valve spool 48 of servo valve 49 to sleeve 39 so that the servo valve spool also moves to the right when the sleeve is so urged by spring 33.

When the engine is cranked for starting, oil is supplied to the valve 49 through an oil supply passage 51 which communicates with a passage 53 in a cylinder 55. The oil then fiows through a passage 57 to an annulus 59 in the spool 48 and from there to a passage 61 in a piston 63 and into a chamber 65. When the oil pressure in chamber 65 becomes great enough, piston 63 will move to the right and urge the fuel pump rack 67 into an excess fuel position.

After the engine starts, the force of flyweights 69 acting against the thrust member 41 forces sleeve 39 to the left as shown in the drawing until the thrust member abuts the adapter 21. This draws the valve spool to the left causing the servo valve to reposition the fuel control rack member. The force exerted by the flyweights will then commence to compress governor spring 19 until the spring force balances the flyweight force in the manner described in the above cited patent to Parks.

If the initial start should prove to be a false start, spring 33 will return the sleeve 39 to the position shown in the drawing as soon as the flyweights cease rotation, thereby returning valve spool 48 to its initial position so as to return the fuel rack to the excess fuel position. In other words, restarting may be performed immediately.

Thus, applicant has provided an engine governor having an excess fuel means which overrides the governor during starting so as to provide suflicient fuel for starting and allowing quick restarting in the event of a false start.

Changes in the structure and dimensions of the invention as illustrated may be made without exceeding the purview of the following claims.

What is claimed is:

1. In an engine governor for controlling the position of a fuel control member in response to the position of rotatable flyweights opposed by a spring, the combination of a hydraulic servo means operatively disposed between said flyweights and said fuel control member, said servo means including a valve spool axially slidably disposed within said servo means and operatively positioned to control the position of said fuel control member, means connecting said spool to said flyweights and said spring such that movement of said flyweights outwardly urges said spool in one direction while movement thereof inwardly urges said spool in the opposite direction; and lost motion means between said flyweights and said spring in the said means connecting said valve spool thereto said lost motion means comprising a sleeve mounted on said valve spool and a biasing means urging said sleeve and said valve spool in a direction so as to position said fuel control means in an excess fuel position when said flyweights are in their maximum inward position.

2. The engine governor of claim 1 including a thrust member acted upon by said flyweights and movable relative to said spring so that the force exerted by said biasing means is overcome before the continued movement of said flyweights becomes directly opposed by the force of said spring.

References Cited UNITED STATES PATENTS 3,145,624 8/1964 Parks of a1. 91-366 FOREIGN PATENTS 377,685 7/ 1932 Great Britain.

PAUL E. MASLOUSKY, Primary Examiner US. Cl. X.R. 91378, 416, 417 

